The invention generally relates to the handling of freight in combined overland and marine transportation and is specifically directed to a freight container adapted to be mounted on railroad double-stack or flat cars, highway truck-trailer chassis and stowed aboard ship. Freight containers which are capable of being stacked in a superimposed relation are known in the prior art to fill the hold and increase deck storage of large sea going vessels. Examples of such containers are disclosed by U.S. Pat. Nos. 3,044,653 and 3,085,703. Containers of this type are provided with heavy steel castings at each of the four front and rear corners of the container. Each corner of the container is provided with a corner post connected between associated pairs of upper and lower steel castings which comprise load bearing members of the containers. Conventional openings in each of the steel castings facilitate the interlocking of the container with suitable lifting means for transferring the container from a land vehicle to a ship and vice versa, as well as to facilitate the positioning and securing together of containers in a stacked relationship. The corner castings are related to the corner post and to the top, side, and endwalls so that the container may be stacked on another with the full load taken by the corner castings and corner posts.
Another container for handling freight is shown by U.S. Pat. No. 3,646,609. This reference provides for the stacking of conventional containers of varied size in superimposed relation. The container is constructed with front and sidewalls formed by metal panels.
The applicant has developed another container for handling stacked chassis and this container is shown and described in U.S. Pat. No. 4,650,381.
The disclosed prior art containers necessitate the use of a three dimensional box shaped structure of continuous framing for purposes of handling freight. Since the freight is of substantial weight and size, it requires a box shaped container with a continuous floor base of sufficient strength and rigidity. The prior art container is a box shaped or platform structure for the conveyance of various commodities and is not a skeletal steel structure for the specific purpose of holding chassis as described by the present invention.
The conventional container chassis and chassis frame are of lengths greater than a standard size freight handling container frame and are of widths equal to that of the container frame. Thus the shipping and loading of a fully assembled container chassis or chassis frame is not easily accomplished unless the chassis are stacked and secured with special lashing gear, conveyed as special oversize cargo atop flat rack containers or within open top containers. The chassis frame is disassembled and packaged or otherwise shipped via a general cargo ship and not onboard a standard container ship, railway car or highway vehicle as containerized freight.
Container shipping companies have for some time been transporting containerized cargo overland atop railway cars (by TOFC and COFC), and more recently by doublestacked, specially dedicated railway cars. The economies provided to the shipper by double-stacked and COFC/TOFC service requires the shipping company to make considerable investment in purchasing and maintaining large fleets of chassis throughout its operating territories, at rail heads, depots and interchange points. This further involves repositioning of empty chassis by highways with resulting transportation costs exceeding that of rail transport.
Off-shore manufacturers of chassis have for some time been exporting chassis from their countries by general cargo (bulk) ships to the United States and other territories. Such shipment involves a freight charge, normally charged per cubic meter. For example, skeletal steel chassis frames shipped by general cargo vessel from Korea, landing on the west coast of the United States at prevailing favorable rates cost the buyer approximately U.S. $45O/unit. Additional costs are involved for dockside handling, in-land transportation, cargo damage, etc. Moreover, if the chassis are shipped atop container flat racks or within open top containers as oversize cargo, the chassis will displace other revenue earning loads onboard container ships. Alternatively, chassis shipped within the confines of special high cube domestic containers, (e.g., 45 foot long, 102 inch wide containers) cannot be easily handled and would be limited to dedicated 45 ft./102 inch operations and would therefore displace other high revenue container freight loads. If chassis are not shipped fully assembled, additional work must be performed to complete assembly in the U.S. at U.S. labor rates. The largest market for chassis sales and demand for chassis vehicles is the east coast of the U.S., but the availability of general cargo ships for east coast discharge is limited, and transit times and freight rates are prohibitive.
By providing the means to quickly, easily transport chassis as containerized freight by railway, highway and onboard container ships, logistical problems are solved, investment in chassis vehicles can be reduced, economies of transportation costs can be realized, and the forementioned costs can be defrayed. The transportation company or container ship operator can reposition its chassis throughout the world as "non-revenue freight, company business."